Aerial bomb



E. C. FRISK. AERIAL BOMB- APPLICATION FILED APR 17.1920.

Patented Feb. 14, 1922;.

2 SHEETS-SHEET l- //YVE/ f 9, v C? F7756 E. 0. FRISK. AERIAL BOMB.-

APPLICATION FILED APR. 17, 1920.

1,40 3 Patented Feb. 14, 1922 2 SHEETS-SHEET 2.

ENOS C. FEISK, OE SOMERSET, "WISCONSIN.

' AERIAL BOMB.

Specification of Letters Patent. Patented Feb. 14, 1922.

Application filed April 17, 1820. Serial No. 374,536.

To all whom. it may concern Be it known that l, Enos C. Fnisn, a citizen of the United States, residing at Semen set, in the county of St. Croix and State of Visconsin, have invented certain new and useful Improvements in Aerial Bombs; and

I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in aerial bombs, and has for its object to provide an efficient, inexpensive, safe and sim-- ple automatic bomb that will burst at a predetermined distance from the earth when dropped from an aeroplane 'or balloon, where the result will be more effective than contact bombs, and more reliable than so- 2 called time fuse bombs in warfare, and, with minor modifications, the improved bomb may be used in scattering fire-extinguishing chemicals and gas to put out forest and other To the above end, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings V Fig. 1 is an elevation of the improved I aerial bomb;

Fig. 2 is a fragmentary detail view principally in central vertical section taken through the lower portion of the bomb, on an enlarged scale;

Fig. 3 is a view corresponding to Fig. 2,

with the exception that the leading weight has been released and the firing pin is about to be released;

Fig. 4 is a fragmentary detail view of the firing pin and associated parts, on an enes larged scale; and

Fig. 5 is a view ofthe leading weight in 'section, taken on the line 5-5 of Fig. 8.

The numeral 6 indicates a shell having upwardly converging walls, having secured to its top a handle 7 by which the bomb may be held. Formed 'in one side of the shell 6, near the handle 7, is a filling opening nor mally closed by a screw plug 8, In the lower end of the shell 6 is an axially located firing pin chamber 9, and directly above this chamber 9 is a detonator chamber 10. .Vithin the chamber 10 is a ballistite powder shell or other fast burning detonator shell 11, having primer 12. This shell 11 is inserted into the chamber 10 through the chamber 9 and is removably held in place by a screw 11. Preferably, the shell 11 will not be placed in the detonator shell 10 until at or near the scene of operation. The shell 6 is filled, through the opening normally closed by the screw plug 8, with lyddite or ptiher powerful explosive, chemicals or the It is, of course, understood that the shell 6 may be made in any desired shape and have double walls to accommodate shrapnel, etc. The bottom of the firing pin chamher 9 is normally closed by a screw plug 18 having an axial opening or seat 14 to receive the depending stem 15 of a firing pin 16. The screw plug 13 is provided with diametrically opposite pin seats 17 for the application of a wrench to turn said screw plug. This screw plug .3,must of course, be removed,

before the shell 11 can be in sorted into the chamber 10 or removed therefrom.

Formed with the firing pin 16, at the upper end of its stem 15, is an annular trigger-engaging flange 1S, and below this flange is an annular shoulder 19 located within the chamber 9. Below the shoulder 19, the stem 15 is provided with a relatively fine-pitch thread. 20. To hold the firingpin stem 15 against rotation in the seat 1 1, but with freedom for endwise movement, there is secured to the screw plug 13 a key 21. mounted in a key-way 22 formed in said stem. A coiled spring 23, encircling the firing pin stem 15, is normally compressed between the screw plug 13 and the flange 18.

To normally hold the firing pin 16 retracted against the action of the compressed spring 23, there is removably applied to the screwthreaded lower end of the stem 15 thereof a winged nut 24 in the form of a propeller, the blades of which are indicated by the numeral 25. These propeller blades 25 are connected by a hub 26, in which the nut 24L is rigidly secured, and which propeller blades are rendered operative, to unscrew said nut from the stem 15 under the action of the air, during the falling of the bomb As previously stated, the winged nut 2-l is screwed onto the stem or" the firing pin 16 and re-acts against the screw plug 13 as a base of resistance and holds said stem with clearance between its shoulder 19 and the upper face of said screw plug to permit a further downward movement of the stem 15 and compression of the spring 23 for a purpose that will presently appear.

A normally retracted trigger 28 is pivoted to a bracket 27 on the inner face of the screw plug 13 and ar anged to be moved into en gagement with the flange 18 and hold the firing pin 16, after the winged nut 2% has been moved out of engagement with the screw plug 13, as will presently appear. A coiled spring 29, anchored to the trigger 28 and bracket 27, is under strain to retract said trigger'and normally hold the same out of engagement with the fiange 18.

To move the trigger 28 into interlocking engagement with the fiange 18 and then release the same, there is provided a leading weight 30 connected to said trigger at an offset point by a cable 31. This cable 31 is normally wound on a reel 32 journaled in the leading weight 30 and loosely extends through a passageway 33 in said leading weight and through an axial passageway 34 in the stem 15, which opens laterally into a notch 35 in the screw plug 18.

Normally, the leading'weight 30 is telescoped onto the lower end of the stem 15 and detachably secured thereto by a cotter pin 36 inserted through aligned bores in said weight and stem. interposed in the cable 31 is a coiled spring 37, which is normally contaiued within the passageway 33 01' the leading weight 30. To withdraw the cotter pin 36 and thereby release the leading weight 30, there is attached to said cotter pin a cable 38 arranged to run under a guide sheave 39 and through a keeper 40 secured to the shell 6 near the handle 7. Attached to the upper end of the cable 31 is a hand ring l1, which normally engages the keeper l0 and holds said cable. The sheare- 39 is journaled in one arm of a skeleton guard 42 secured to the lower end of the shell 6 and arranged to cover the propeller blades 25 and leading weight 30. In the bottom of the guard 41 is a relatively large annular opening 413, through which the leading'weight 30 and cable 31 are free to move when said leading weight is released by the withdrawal of tlie cotter pin 36. A key, or other suital'ile tool, not shown, may be applied to the shaft of the reel 32 for turning the same towind the cable 31 thereon.

To control the speed, at which the leading weight 30 will drop when released, and to pr-rent back lash of the cable 31. there is proyided a f iction brake operatire on the reel 32. This friction brake, as shown, comprises a-fibre shoe 4% in the'form ofa bolt mounted in the leading weight 30 and yieldingly held in contact with the reel 32 by a coiled spring 45 held under a variable pressure by screw plug 46.

'To operate the bomb preliminary to exploding, the same is held by the handle 7, and while thus held, the cotter pin 36 is withdrawn by pulling on the hand ring 411 to release the leading weight 30. ts the leading weight 80 drops, the cable 31, which is of a predetermined length, is unwound from the reel 32 and, at the completion of its unwinding, the spring absorbs the shock due to the stopping of: said leading weight. The action of the leading weight 30, acting through the unwound cable 31 and spring37, moves the trigger 28 against the tension of the spring 29 into interlocking engagement with the flange 18 and further retracts the firing pin16 against the action of the spring 23 until stopped by the shoulder 19. This further retraction of the firing pin 16 moves the nut 2t and hub 26 out of engagement with the screw plug 13 to permit free turning movement of the propellerblades 25 under the action of the air during the falling of the bomb to unscrew the nut 24 from the stem 15. When the leading weight 30 strikes the ground or target, the slack produced in the cable 31 will release the trigger 28 and allow the spring 29 to retract the same and thereby release the firing pin 16. The released firing pin 16 will be driven under the action of the spring 23 against the primer 12, to ignite the detonator and thereby set off the explosives, or chemicals Z. In place of the spring a cylinder and piston may be used.

What Iclaim is:

1. In an aerialbomb, the combination with a shell, of a normally retracted firing pin a normally compressed spring tending to project said pin, a propeller and co-operating means normally holding the firing pin retracted and said spring compressed, but rendered operative by the falling of the bomb to be disengaged from the firing pin, supplemental means adapted to hold said spring comgressed and said pin retracted, a normally held leading weight, a cable connecting the leading weight to the trigger, said leading weight, when released, adapted to move said supplemental means into a position to retain the firing pin in retracted-position, when released by the propeller and 00- operating means, and then to release said supplemental means when coming in y contact with the earth or target.

2. in an aerial bomb, the combination with a shell, of a normally retracted firing pin, a normally compressed spring tending to project said pin, a propeller and co-operating means normally engaging the firing pin and holding the same retracted, but rendered operative by the falling of the bomb to disengage the vfiring pin, a normally retracted incense trigger, a normally held leading weight, a

reel journaled on the leading weight, a cable attached to the trigger and arranged to be wound onto the reel, said leading weight, When released, adapted to move and hold the trigger in a position to retain the firing pin retracted and said spring compressed, when released by the propeller and co-operating means, and then release the trigger when coming in contact with the earth or target, and a brake for controlling the movement of the reel during the unwinding of the cable therefrom.

3. In an aerial bomb the combination with a shell, of a normally retracted firing pin, a normally compressed spring tending to project said pin, a propeller and co-operating means normally holding the firing pin retracted and said spring compressed, but rendered operative by the falling of the bomb to release the firing pin, a normally retracted trigger, means under strain to retract the trigger, a normally held leading weight, a reel journaled on the leading weight, a cable attached to the trigger and arranged to be wound onto the reel, said leading weight, when released, adapted to move and hold the trigger in a position to retain the firing pin, when released by the propeller and co-operating means, and then release the trigger when coming in contact with the earth or target, a friction brake for controlling the movement of the reel during the unwinding of the cable therefrom and means for varying the amount of friction on said brake.

4. In an aerial bomb, the combination with a shell, of a normally retracted firing pin, a normally compressed spring tending to project said pin, a propeller and co-operating means normally holding the firing pin retracted, but rendered operative by the falling of the bomb to release the firing pin, a normally retracted trigger, means under strain to retract the trigger, a normally held leading weight, a cable connecting the lead ing weight to the trigger, said leading weight, when released, adapted to move and hold the trigger n a position to retain the firing pin retracted and said spring compressed, when released by the propeller and co-operating means, and then release the trigger when coming in contact with the earth or target, and means for controlling the falling speed of said leading weight.

5. In an aerial bomb, thecombination with a shell,of normally retracted spring-pro jected firing pin having a stem working through a part on the shell, apropellerblade-equipped nut having screw-threaded engagement with the stem of the firing pin and engaging said part on the shell as a base of resistance to normally hold the firing pin retracted but renderedoperative by the falling of the bomb to release the firing pin, a normally retracted trigger, a normally held leading weight, and a cable connecting the leading weight to the trigger, said leading weight, when released, adapted to move the trigger into engagement with the firing pin to further retract the same and thereby move said nut out of engagement with the part on the shell, said nut, under the action of the falling of the bomb, arranged to be unscrewed from the stem of the firing pin, said leading weight, when coming in contact with the earth or target, arranged to move the trigger into an inoperative position and thereby release the firing pin.

6. In an aerial bomb, the combination with a shell, of a normally retracted spring-projected firing pin having a stem working through a part on the shell, a propellerblade-equipped nut having serew-threaded engagement with the stem of the firing pin and engaging said part on the shell as a base of resistance to normally hold the firing pin retracted but rendered operative by the falling of the bomb to release the firing pin, a normally retracted trigger, a leading Weight telescoped onto the steam of the firing pin,

means for temporarily locking the leading weight to the stem of the firing pin and for releasing the same, and a cable connecting the leading weight to the trigger, said leading weight, when released, adapted to move and hold the trigger in a position to retain the firing pin, when released by the propeller, and then release the trigger when coming in contact with the earth or target.

7. An aerial bomb having in combination a shell, a detonator shell and a firing pin chamber located in one end thereof, a normally retracted spring projected firing pin located in and projecting from said chamher through one end of the same, a propellerblade-equipped nut having screw-threaded engagement with the stem of the firing pin and located outside of said chamber, a normally retracted trigger, a leading weight telescoped about the portion'of the firing pin outside of said chamber, means for temporarily locking the leading weight to the stem of the firing pin and for releasing the same, and means connecting the leading weight to the stem of the firing pin for releasing the same, said propeller and leading weight being enclosed by an open guard member having a central aperture therein through which the leading weight is arranged to pass, said guard having a portion thereof forming a handle for holding the said bomb.

8. An aerial bomb having in combination a shell adapted to contain an explosive, a normally retracted firing pin, a normally compressed spring tending to project said pin, a propeller means for releasing said pin, normally inoperative supplemental means for holding the pin retracted and said spring -ing the ground to release the firing pin to compressed, and means operated by the falldetonate the bomb.

ing of a leading Weight for moving said sup- In testimony whereof I vafiix my signature plemental means into position to hold said in presence oftwo witnesses.

pin retracted and said spring compressed ENOS C. FRISK. after the same are released by said propeller means, said supplemental means being adapted to be released by the leading Weight strik- \Vitnesses ALICE F. LA GRANDEUR, I H. A. LAGRANDEUR. 

